1. Field of the Invention
The present invention relates generally to a hinge, and more particularly to a hinge used for folding portable electronic devices.
2. Prior Art
Hinges are almost universally used in modern portable electronic devices such as mobile phones and PDAs (Personal Digital Assistants). These portable electronic devices typically comprise two housings. Hinges are used to join the two housings together, and to enable one housing to be folded upon the other one. Normally, one of the housings is called a body and contains most of the electronic components of the portable electronic device. The other housing is called a cover and contains fewer or even no electronic components.
One kind of hinge is disclosed in U.S. Pat. No. 6,292,980 issued to Young-Jin Yi et al (the '980 patent). In the '980 patent, as shown in FIG. 5, a hinge mechanism 500 includes: a cam 510 having a mountain-shaped portion 512 on one end, and a shaft portion 514 on the other end which is used for engaging a cover of the mobile phone; a corresponding cam follower 520 having a bottom wall 522; and a spring 530 used for pressing the cam follower 520 to resist on the cam 510. The cam 510, the cam follower 520 and the spring 530 are all contained in a hinge housing 540, and covered by a hinge cover 550. The hinge housing 540 and hinge cover 550 are engaged in a body of the mobile phone. In use, the mountain-shaped portion 512 moves along the bottom wall 522. The cam 510 together with the cover rotates relative to the body of the mobile phone in a predetermined direction. However, the scope of rotation of the cover is limited. Many modern portable electronic devices need a cover thereof to be able to rotate to a variety of orientations.
Therefore, a hinge with a relatively simple structure is desired to overcome the above-described limitations.